Glasses with low excess modifier content

Abstract

A glass composition includes: from 55.0 mol % to 70.0 mol % SiO 2 ; from 12.0 mol % to 20.0 mol % Al 2 O 3 ; from 5.0 mol % to 15.0 mol % Li 2 O; and from 4.0 mol % to 15.0 mol % Na 2 O. The glass composition has the following relationships −8.00 mol %≤R 2 O+RO−Al 2 O 3 −B 2 O 3 −P 2 O 5 ≤−1.75 mol %, 9.00≤(SiO 2 +Al 2 O 3 +Li 2 O)/Na 2 O, and (Li 2 O+Al 2 O 3 +P 2 O 5 )/(Na 2 O+B 2 O 3 )≤3.50. The glass composition may be used in a glass article or a consumer electronic product.

What is claimed is: 
     
       1. A glass article comprising:
 a first surface; 
 a second surface opposite the first surface, wherein a thickness (t) of the glass article is measured as a distance between the first surface and the second surface; and 
 a compressive stress layer extending from at least one of the first surface and the second surface into the thickness (t) of the glass article, wherein 
 a central tension of the glass article is greater than or equal to 60 MPa, 
 the compressive stress layer has a depth of compression that is from greater than or equal to 0.15t to less than or equal to 0.25t, and 
 the glass article is formed from a glass, and/or has a composition at a center depth of the glass article, comprising:
 from greater than or equal to 55 mol % to less than or equal to 70.0 mol % SiO 2 ; 
 from greater than or equal to 12.0 mol % to less than or equal to 20.0 mol % Al 2 O 3 ; 
 from greater than or equal to 5.0 mol % to less than or equal to 10.0 mol % Li 2 O; 
 from greater than or equal to 4.0 mol % to less than or equal to 10.0 mol % Na 2 O; and 
 greater than 0.0 mol % P 2 O 5 , 
 greater than 1.0 mol % B 2 O 3 , 
 wherein:
 Al 2 O 3 +Li 2 O is greater than 22.0 mol %. 
 
 
 
     
     
       2. The glass article of  claim 1 , P 2 O 5  is present in an amount of greater than 0.5 to less than or equal to 5.0 mol %. 
     
     
       3. The glass article of  claim 1 , wherein Al 2 O 3 +Li 2 O is less than or equal to 26.5 mol %. 
     
     
       4. The glass article of  claim 1 , wherein, in mol %, 1.50≤(Li 2 O+Al 2 O 3 +P 2 O 5 )/(Na 2 O+B 2 O 3 )≤3.50. 
     
     
       5. The glass article of  claim 1 , wherein, in mol %, 1.00≤(Li 2 O+Al 2 O 3 )/(Na 2 O+B 2 O 3 +P 2 O 5 )≤2.75. 
     
     
       6. The glass article of  claim 1 , wherein A 1   2 O 3 +Li 2 O+Na 2 O is greater than 25.0 mol % to less than or equal to 30.0 mol %. 
     
     
       7. The glass article of  claim 1 , wherein, in mol %, Al 2 O 3 /(R 2 O+RO) is from greater than 0.90 to less than 1.20, wherein RO is the sum of divalent cation oxides and R 2 O is the sum of alkali metal oxides. 
     
     
       8. The glass article of  claim 1 , wherein, in mol %, 1.0≤(Al 2 O 3 +B 2 O 3 +P 2 O 5 )/(R 2 O+RO)≤1.8, wherein RO is the sum of divalent cation oxides and R 2 O is the sum of alkali metal oxides. 
     
     
       9. The glass article of  claim 1 , wherein the glass article has a liquidus viscosity from greater than or equal to 20 kP to less than 1000 kP. 
     
     
       10. The glass article of  claim 1 , wherein the central tension of the glass article is greater than or equal to 80 MPa. 
     
     
       11. The glass article of  claim 1 , wherein the central tension of the glass article is greater than or equal to 90 MPa. 
     
     
       12. The glass article of  claim 1 , wherein the compressive stress layer has a depth of compression that is from greater than or equal to 0.18t to less than or equal to 0.22t. 
     
     
       13. A consumer electronic product, comprising:
 a housing comprising a front surface, a back surface and side surfaces; 
 electrical components at least partially within the housing, the electrical components comprising at least a controller, a memory, and a display, the display at or adjacent the front surface of the housing; and 
 a cover substrate disposed over the display, 
 wherein at least a portion of at least one of the housing and the cover substrate comprises the glass article of  claim 1 . 
 
     
     
       14. A glass composition comprising:
 from greater than or equal to 55 mol % to less than or equal to 70.0 mol % SiO 2 ; 
 from greater than or equal to 12.0 mol % to less than or equal to 20.0 mol % Al 2 O 3 ; 
 from greater than or equal to 5.0 mol % to less than or equal to 10.0 mol % Li 2 O; 
 from greater than or equal to 4.0 mol % to less than or equal to 10.0 mol % Na 2 O; and 
 greater than 0.0 mol % P 2 O 5 , 
 greater than 1.0 mol % B 2 O 3 , 
 wherein:
 Al 2 O 3 +Li 2 O is greater than 22.0 mol %. 
 
 
     
     
       15. The glass composition of  claim 14 , P 2 O 5  is present in an amount of greater than 0.5 to less than or equal to 5.0 mol %. 
     
     
       16. The glass composition of  claim 14 , wherein Al 2 O 3 +Li 2 O is greater less than or equal to 26.5 mol %. 
     
     
       17. The glass composition of  claim 14 , wherein Al 2 O 3 +Li 2 O+Na 2 O is greater than 25.0 mol % to less than or equal to 30.0 mol %. 
     
     
       18. The glass composition of  claim 14 , wherein 6.96Al 2 O 3 −1.90B 2 O 3  +2.16CaO+3.30MgO−1.50Na 2 O+12.74Li 2 O −1.10SrO−14.50K 2 O−1.87La 2 O 3 +6.13ZrO 2 −76.40>50.00 mol %, wherein amounts of components are in mol %. 
     
     
       19. The glass composition of  claim 14 , wherein, in mol %, 1.50≤(Li 2 O+Al 2 O 3 +P 2 O 5 )/(Na 2 O+B 2 O 3 )≤3.50. 
     
     
       20. The glass composition of  claim 14 , wherein, in mol %, 1.00≤(Li 2 O+Al 2 O 3 )/(Na 2 O+B 2 O 3 +P 2 O 5 )≤2.75.